KR101461777B1 - A biodegradable polymer composition comprising cellulose and polylactic acid, and a biodegradable film prepared by using the same - Google Patents

Abstract

The present invention relates to a biodegradable resin composition comprising cellulose and polylactic acid and a biodegradable film produced using the same. More particularly, the present invention relates to a biodegradable resin composition comprising cellulose, polylactic acid, a peroxidic agent and an antioxidant modified with a reactive modifier The present invention relates to an environmentally friendly biodegradable resin composition having excellent mechanical properties and biodegradability, and a biodegradable film produced using the composition.

Description

[0001] The present invention relates to a biodegradable resin composition comprising cellulose and polylactic acid, and a biodegradable film using the biodegradable resin composition and a biodegradable film prepared by using the same.

The present invention relates to a biodegradable resin composition comprising cellulose and polylactic acid, and a biodegradable film produced using the biodegradable resin composition. More particularly, the present invention relates to an environmentally friendly biodegradable resin composition having improved mechanical properties and excellent economy, To a biodegradable film.

Synthetic resins such as polyethylene, polystyrene, polypropylene and polyvinyl chloride have been used extensively in garbage bags, roll bags, shopping bags, food packaging, building materials and household appliances in a wide range of industries and are inextricably linked to everyday life Respectively. Although these synthetic resins have excellent durability, they have poor degradability in a natural state, which adversely affects the ecosystem at the time of disposal after use and causes environmental destruction. Among these resins, the above-mentioned resins have a high proportion of disposable products, which is a serious problem in society and causes an increase in economic costs.

A biodegradable resin is used as a solution to the above problem. Examples of the biodegradable resin include a cellulose-based resin, a starch-based resin, and a biodegradable polyester-based resin. These resins are biodegradable due to the action of enzymes produced by environmentally existing microorganisms and can be decomposed into low molecular substances and ultimately decomposed into water and carbon dioxide.

Cellulose is the most abundant natural polymer material on the planet. It is mainly composed of wood or cotton. It is used in many fields such as fiber, paper, food processing, building materials and medicine because of its excellent regeneration and biodegradability. Various derivatives can be obtained by substituting the -OH group in the cellulose molecule through acetylation or etherification. When the -OH group is modified as described above, the intermolecular hydrogen bonding can be suppressed, and thus the increase of the solubility can be expected. Cellulose derivatives produced by this method include cellulose nitrate (CN), cellulose acetate (CA), cellulose diacetate (CDA), cellulose propionate (CAP), methyl cellulose (MC) and ethyl cellulose .

On the other hand, biodegradable polyester resins include polyglycolic acid, polyhydroxybutyric acid, polylactic acid and the like. The production cost of polyglycolic acid and polyhydroxybutyric acid obtained by the biosynthesis is high, while the price of polylactic acid is comparable to that of conventional polyolefin-based resin, and economic efficiency can be secured. In addition, polylactic acid is a kind of linear aliphatic thermoplastic polyester which is capable of melt spinning and molding and exhibits good physical properties such as high tensile strength, thermoplasticity and processability, and has a structure suitable for decomposition into a natural product. However, polylactic acid is very poor in flexibility and tear properties, and is easily torn when it is made into a film, and it is difficult to blow molding.

Under these circumstances, the inventors of the present invention have found that by modifying cellulose with a reactive modifier, and then mixing the cellulose modified with the reactive modifier with polylactic acid, a peroxide, and an antioxidant at a certain mixing ratio, the compatibility with cellulose and polylactic acid The present invention provides an environmentally friendly biodegradable resin composition capable of improving mechanical properties such as tensile strength and impact strength and maintaining biodegradability, and a film using the same.

Japanese Patent Application Laid-Open No. 10-2012-0047431 (Publication date 2012.05.14.); Japanese Patent Application Laid-Open No. 07-102114 (published on April 18, 1995)

It is an object of the present invention to provide an environmentally friendly biodegradable resin composition having improved mechanical properties and excellent economy.

Another object of the present invention is to provide a biodegradable film produced using the biodegradable resin composition.

In order to solve the above problems, the present invention provides a biodegradable composition comprising 10-90 parts by weight of cellulose modified with a reactive modifier, 10-90 parts by weight of polylactic acid, 0.06-0.6 parts by weight of peroxide, and 0.3-0.8 parts by weight of an antioxidant To provide a resin composition.

The present invention relates to a cellulose acylate film comprising cellulose modified with a reactive modifier, a polylactic acid, a peroxidizing agent, and an antioxidant, wherein the mixing ratio of cellulose modified with a reactive modifier and polylactic acid is controlled within a certain range, Wherein the biodegradable resin composition is an environmentally friendly biodegradable resin composition. In particular, the present invention can improve the compatibility with polylactic acid by using cellulose modified with a reactive modifier, thereby improving the mechanical properties such as tensile strength, impact strength and the like and maintaining biodegradability.

In the present invention, the cellulose may be selected from the group consisting of cellulose nitrate (CN), cellulose acetate (CA), cellulose diacetate (CDA), cellulose propionate (CP), methylcellulose methyl cellulose (MC), and ethyl cellulose (EC).

In the present invention, the cellulose modified with the reactive modifier may be obtained by adding 0.5 to 2.5 parts by weight of a reactive modifier, 0.06 to 0.6 part by weight of a reactive modifier, and 0.3 to 0.8 part by weight of an antioxidant to 100 parts by weight of cellulose, followed by melt kneading.

The term "reactive modifier " used in the present invention means a compound having a molecular weight of 1000 or less among the polar acid anhydrides or anhydrides thereof, and is copolymerized with cellulose to increase the compatibility And mechanical properties such as tensile strength and impact strength can be improved when mixed with polylactic acid.

In the present invention, the content of the reactive modifier is 0.5 to 2.5 parts by weight based on 100 parts by weight of the cellulose. If the content is less than 0.5 parts by weight, the effect of improving the mechanical properties is difficult to be expected. If the content is more than 2.5 parts by weight, the cost increases, the discoloration of the raw material and the increase of adverse reaction are caused to reduce the quality of the product, Can be degraded.

In the present invention, the reactive modifier may include vinyl silane, glycidyl methacrylate, styrene acrylonitrile, acrylic acid, fumaric acid, It is also possible to use a mixture of citraconic anhydride, maleic anhydride, isooctadecenylsuccinic anhydride and N-hexadecenylsuccinic anhydride. May be used singly or in combination, but the present invention is not limited thereto.

In the present invention, the content of the peroxide is 0.06 to 0.6 parts by weight per 100 parts by weight of the cellulose when the cellulose is modified. If the content is less than 0.06 part by weight, the effect of modifying by the reactive modifier is small, and the object to be achieved by the present invention is difficult to achieve. If the content is more than 0.6 part by weight, excessive gelation due to networking between main chains occurs It can also result in damage to the appearance of the film during film forming and inevitably the result of incapability of molding due to damage of the film in the molding process.

In the present invention, in the modification of the cellulose, the peroxide is selected from the group consisting of dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, t-butyl peroxylaurate, t- Butyl peroxyacetate, di-t-butyl diperoxyphthalate, t-dibutylperoxymaleic acid, t-butylcumylperoxide, t-butyl hydroperoxide, 1,3-bis (t-butylperoxyisopropyl) , Methyl ethyl ketone peroxide, di- (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5- , 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide, and n-butyl- t-butyl peroxy) valerate.

In the present invention, the content of the antioxidant when the cellulose is modified is 0.3 to 0.8 parts by weight based on 100 parts by weight of the cellulose. If the content is less than 0.3 part by weight, it is difficult to achieve the structural protection of the cellulose from the heat history generated during processing. If the content is more than 0.8 part by weight, excessive use may lead to a transition in the process of using the film, And the like.

In the present invention, when the cellulose is modified, the antioxidant may be selected from the group consisting of pentaerythritol tetrakis (3,5-di-tert-butylhydroquinone) butyl-4-hydroxyhydrocinnamate) and tris (2,4-di-tert-butylphenyl) phosphite.

In the present invention, the melt-kneading at the time of modifying the cellulose may be carried out in an extruder.

The extruder which can be used in the present invention is not particularly limited as long as it has good known mixing properties such as a single-screw extruder, a co-rotating twin-screw extruder and a bi-directional twin-screw extruder, but most preferably, It is good.

The term " poly (lactic acid), PLA ", as used herein, means a polymer comprising lactic acid units. Specifically, the lactic acid may be L-lactic acid, D-lactic acid, or a combination thereof.

In the present invention, the mixing of the cellulose modified with the reactive modifier and the polylactic acid is carried out in order to maintain the biodegradability while improving the mechanical properties, and the mixing weight ratio is 10 to 90 parts by weight: 10 to 90 parts by weight do. If it is out of the above range, it is difficult to expect an increase in the economical efficiency expected by mixing and a mutual complement of mechanical properties.

In the present invention, the peroxidizing agent and the antioxidant contained in the biodegradable resin composition may be the same kinds as those used in the modification of the cellulose.

Preferably, the biodegradable resin composition of the present invention may further include an inorganic filler to increase the crystallization speed and increase the moldability during the molding process.

In the present invention, the inorganic filler may preferably have an average particle size of 0.5 to 5 mu m. When the average particle size of the inorganic filler is less than 0.5 탆, it becomes difficult to disperse the particles. When the average particle size exceeds 5 탆, the particle size becomes too large and it is difficult to achieve the object of the invention.

In the present invention, as the inorganic filler, at least one selected from the group consisting of hard or heavy calcium carbonate, silica, talc, barium sulfate, clay and calcium oxide may be used singly or in combination.

In the present invention, the content of the inorganic filler is preferably 2 to 13% by weight of the total composition. If the content of the inorganic filler is less than 2% by weight of the total composition, the effect of contributing to the crystallization rate is small. If the content of the inorganic filler is more than 13% by weight, dispersion of the inorganic filler is difficult and mechanical properties may be deteriorated. .

In the present invention, the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 캜) of the biodegradable resin composition may preferably be 3 to 30 g / 10 min, more preferably 5 to 20 g / 10 min. By controlling the melt index within the above range, the workability of the composition can be improved and mechanical properties such as tensile strength and elongation can be improved. Further, by controlling the melt index in the above range, the process can be simplified and the production cost can be reduced. Accordingly, excellent workability and mechanical properties can be exhibited by the composition.

The biodegradable resin composition of the present invention may contain various additives such as a stabilizer, a lubricant, a flame retardant, an antistatic agent, an antibacterial agent, a biodegradation accelerator, a heat stabilizer, a light stabilizer, a weather stabilizer, an ultraviolet absorber, And the like.

Also, the present invention provides a biodegradable resin composition comprising 10 to 90 parts by weight of cellulose modified with a reactive modifier, 10 to 90 parts by weight of polylactic acid, 0.06 to 0.6 part by weight of peroxide, and 0.3 to 0.8 part by weight of an antioxidant, To provide a biodegradable film.

The present invention relates to a biodegradable resin composition obtained by extruding a biodegradable resin composition obtained by mixing cellulose modified with a reactive modifier with polylactic acid, a peroxidizing agent and an antioxidant in a certain mixing ratio to produce an environmentally friendly biodegradable Film is provided. In particular, the present invention can improve the compatibility with polylactic acid by using cellulose modified with a reactive modifier, thereby improving the mechanical properties such as tensile strength, impact strength and the like and maintaining biodegradability.

In an experimental example of the present invention, when a cellulose modified with a reactive modifier and a polylactic acid were mixed, an increase in the interfacial adhesion due to the modified cellulose, compared with the case of using an unmodified cellulose and polylactic acid, And the biodegradability was maintained at a similar level or improved (Experimental Example 1, Table 1) as the mechanical properties were improved.

In the present invention, the extruder which can be used for extruding the biodegradable resin composition or film is not particularly limited as long as it has a well-known mixing property such as a single-screw extruder, a co-rotating twin-screw extruder, Preferably, a co-rotating twin-screw extruder is used.

In the present invention, the extrusion temperature of the biodegradable resin composition or film may be 130 to 180 캜.

The present invention relates to a cellulose acylate film comprising cellulose modified with a reactive modifier, a polylactic acid, a peroxidizing agent, and an antioxidant, wherein the mixing ratio of cellulose modified with a reactive modifier and polylactic acid is controlled within a certain range, The biodegradable resin composition of the present invention can provide an environmentally friendly biodegradable resin composition. In addition, the biodegradable resin composition of the present invention is suitable for processing the melt index, which can shorten the processing time and reduce the production cost. Further, since the biodegradable resin composition of the present invention is processed into a biodegradable film, the biodegradability of the biodegradable resin composition can be improved and the mechanical properties thereof can be improved and improved.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Manufacturing example  One: As a reactive modifier Reformed  Cellulose manufacture

1 part by weight of 18 ASA (isooctadecenylsuccinic anhydride, Albemarle), 0.1 part by weight of dicumyl peroxide as a peroxide and 0.3 part by weight of an antioxidant were added to 100 parts by weight of cellulose diacetate (hereinafter referred to as CDA) After preliminary mixing, extruded in a co-axial twin-screw extruder. The antioxidant used herein was a mixture of 0.15 parts by weight of Anox 20 (Chemtura Corporation) and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation).

The temperature condition of the extruder was 130/140/150/160/160/170/160/160/170/170 ° C. and the rpm of the screw was extruded at a feeder of 70 to 80 rpm and a main motor of 450 rpm.

Example  1: Preparation of biodegradable resin composition and film using the same

0.1 part by weight of dicumyl peroxide, 0.15 part by weight of Anox 20 (Chemtura Corporation) as an antioxidant, and 0.1 part by weight of a polyalkylene oxide of Alkanox (trade name) were added to 100 parts by weight of the modified CDA and polylactic acid of Preparation Example 1, 240 (Chemtura Corporation) were premixed. At this time, the melt index (ASTM D1238, 2.16 kg / cm 2, 190 캜) of the premix was 6.8 g / 10 min. The premix was extruded in an extruder. The temperature condition of the extruder was 150/160/170/180/160/170/170/180/180/180 ° C. and the screw rpm was extruded at feeder 60 rpm and main motor 370 rpm.

The biodegradable resin composition thus prepared was adjusted to an extruder cylinder and a die temperature in the range of 130-170 ° C. by using a round die molding machine to prepare a tubular film having a width of 300 mm and a thickness of 30 μm.

Example  2: Biodegradable resin composition and production of film using the same

0.06 part by weight of dicumyl peroxide, 0.15 part by weight of Anox 20 (Chemtura Corporation) as an antioxidant, and 0.1 part by weight of an alkoxyl group as an antioxidant were added to 100 parts by weight of the modified CDA and polylactic acid of Preparation Example 1, 240 (Chemtura Corporation) were premixed. At this time, the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C) of the premix was 8.3 g / 10 min. The premix was extruded in an extruder. The temperature condition of the extruder was 150/160/170/180/160/170/170/180/180/180 ° C. and the screw rpm was extruded at feeder 60 rpm and main motor 370 rpm.

The biodegradable resin composition thus prepared was adjusted to an extruder cylinder and a die temperature in the range of 130-170 ° C. by using a round die molding machine to prepare a tubular film having a width of 300 mm and a thickness of 30 μm.

Example  3: Biodegradable resin composition and production of film using the same

0.06 part by weight of dicumyl peroxide, 0.15 part by weight of Anox 20 (Chemtura Corporation) as an antioxidant, and 0.1 part by weight of an alkoxyl group as an antioxidant were added to 100 parts by weight of the modified CDA and polylactic acid of Preparation Example 1, 240 (Chemtura Corporation) were premixed. At this time, the melt index (ASTM D1238, 2.16 kg / cm 2, 190 캜) of the premix was 5.5 g / 10 min. The premix was extruded in an extruder. The temperature condition of the extruder was 150/160/170/180/160/170/170/180/180/180 ° C. and the screw rpm was extruded at feeder 60 rpm and main motor 370 rpm.

The biodegradable resin composition thus prepared was formed into a tubular film having a thickness of 300 mm and a thickness of 30 탆 by appropriately adjusting the extruder cylinder and the die temperature in the range of 130 to 170 캜 using a round die molding machine.

Comparative Example  1: Preparation of biodegradable resin composition and film using the same

After the unmodified CDA and polylactic acid were dried, 100 parts by weight of 70:30 by weight of the mixture was mixed with 0.15 part by weight of Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) as antioxidants These were premixed and extruded in an extruder. The temperature condition of the extruder was 150/160/170/180/160/170/170/180/180/180 ° C. and the screw rpm was extruded at feeder 60 rpm and main motor 370 rpm.

The biodegradable film composition thus prepared was adjusted to an extruder cylinder and a die temperature in a range of 170 to 190 캜 by using a round die molding machine to prepare a tubular film having a thickness of 30 탆.

Comparative Example  2: Biodegradable resin composition and production of film using the same

After the unmodified CDA and polylactic acid were dried, 100 parts by weight of 30:70 by weight of the mixture was mixed with 0.15 part by weight of Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) as antioxidants These were premixed and extruded in an extruder. The temperature condition of the extruder was 150/160/170/180/160/170/170/180/180/180 ° C. and the screw rpm was extruded at feeder 60 rpm and main motor 370 rpm.

The biodegradable film composition thus prepared was formed into a tubular film having a thickness of 30 탆 by appropriately adjusting the extruder cylinder and the die temperature in the range of 170 to 190 캜 using a round die molding machine.

Experimental Example 1: Measurement of mechanical properties and biodegradability of a film using a biodegradable resin composition

In order to evaluate the physical properties of the films using the biodegradable resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 and 2, the mechanical properties and biodegradability of each film were measured.

First, tensile strength and elongation were measured as mechanical properties. 7.6 Tensile Strength and Tensile Elongation of KS M 3503 The strength (kg / ㎠) and elongation (%) of samples were measured according to the test method. (TD), which is perpendicular to the running direction (MD) and the running direction, respectively, and then the lowest value was taken.

In addition, the biodegradability was evaluated by measuring the amount of carbon dioxide generated from the standard sample (cellulose) and the test sample by the method of measuring the aerobic biodegradability of the plastic under the composting condition of KS M 3100-1 and using the following formula.

Biodegradability (%) = (amount of carbon dioxide generated / amount of theoretical carbon dioxide) * 100

The measurement results are shown in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 The tensile strength 30.21 35.16 32.26 14.54 20.92 Modulus 1578 1995 1880 1083 1106 Biodegradation (45 days,%) 70 65 64 62 60

As can be seen from the above Table 1, Examples 1 to 3 according to the present invention show improved compatibility with PLA due to an increase in interfacial adhesion by modified cellulose as compared with Comparative Examples 1 and 2, Can be found.

In addition, it can be seen that Examples 1 to 3 according to the present invention are maintained at a similar level of biodegradability as compared with Comparative Examples 1 to 2, or improved to be more than that.

Claims (12)

10 to 90 parts by weight of cellulose modified with a reactive modifier, 10 to 90 parts by weight of polylactic acid, 0.06 to 0.6 part by weight of peroxide, and 0.3 to 0.8 part by weight of an antioxidant.
The biodegradable resin composition according to claim 1, wherein the cellulose is at least one selected from the group consisting of cellulose nitrate, cellulose acetate, cellulose diacetate, cellulose propionate, methyl cellulose and ethyl cellulose.
The cellulose modified with the reactive modifier according to claim 1, which is obtained by adding 0.5 to 2.5 parts by weight of a reactive modifier, 0.06 to 0.6 part by weight of a reactive modifier, and 0.3 to 0.8 part by weight of an antioxidant to 100 parts by weight of cellulose, And a biodegradable resin composition.
The process of claim 3, wherein the reactive modifier is selected from the group consisting of vinyl silane, glycidyl methacrylate, styrene acrylonitrile, acrylic acid, fumaric acid, citraconian hydride, maleic anhydride, isooctadecenylsuccinic anhydride And N-hexadecenylsuccinic anhydride. The biodegradable resin composition according to claim 1,
The process according to claim 1, wherein the peroxide is selected from the group consisting of dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, t-butyl peroxylaurate, T-butylperoxyisophthalate, t-butylperoxymaleic acid, t-butylcumylperoxide, t-butylhydroperoxide, 1,3-bis (t- butylperoxyisopropyl) benzene, methylethyl Di- (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5- Di (t-butylperoxy) hexane, di-t-butylperoxide, and n-butyl- Peroxy) valerate. ≪ / RTI >
The antioxidant according to claim 1, wherein the antioxidant is selected from the group consisting of pentaerythritol tetrakis (3,5-di-t-butyl-4-hydroxyhydrocinnamate) and tris 2,4-di-t-butylphenyl phosphite Wherein the biodegradable resin composition is at least one selected from the group consisting of
The biodegradable resin composition according to claim 1, further comprising an inorganic filler.
8. The biodegradable resin composition according to claim 7, wherein the inorganic filler has an average particle size of 0.5 to 5 mu m.
The biodegradable resin composition according to claim 7, wherein the inorganic filler is at least one selected from the group consisting of hard or heavy calcium carbonate, silica, talc, barium sulfate, clay and calcium oxide.
The biodegradable resin composition according to claim 7, wherein the content of the inorganic filler is 2 to 13% by weight of the total composition.
The biodegradable resin composition according to claim 1, wherein the composition has a melt index (ASTM D 1238, 2.16 kg / cm 2, 190 캜) of 3 to 30 g / 10 min.
A biodegradable film obtained by extruding the biodegradable resin composition of any one of claims 1 to 11.